Bioluminescence
Bioluminescence is the light that living things make inside their own bodies.
A jar of clear liquid sits on a dark kitchen counter. Inside it, tiny glowing dots float near the bottom. The dots make their own light — they do not need a bulb or flame. Each dot glows because of a chemical change happening inside it.
Explaining bioluminescence by grade level
Fireflies glow at night to find a mate. They mix two things inside their body to make light. No heat comes from this glow. It is like a tiny cold lamp that turns on and off.
Projects that explore bioluminescence
Fireflies produce light through a chemical reaction with four ingredients: luciferin, luciferase, ATP, and oxygen. The reaction happens in the firefly's abdomen and produces cold light at 96% efficiency. Each species flashes a unique pattern, and males and females find each other by recognizing their own signal. Scientists have extended this chemistry into new territory — NASA has explored mixing firefly compounds with samples to detect ATP on other planets, and biologists use luciferase to test how well antibiotics fight tuberculosis.
Some ocean bacteria produce their own light through bioluminescence, and this project uses that glow as a pollution detector. When harmful substances interfere with the bacteria, the light fades. You transfer the bacteria into test tubes and add pollutants one at a time — hair gel, 3-in-1 oil, tap water, and Hudson River water. To measure the effect, you count how many sheets of paper it takes to block the glow. Hair gel cut the light by 75 percent. Tap water and river water each reduced it by 20 percent. The oil had no effect at all.
Bioluminescence is the light that living things make inside their own bodies. This project tests whether luminescent bacteria will grow and glow on an agar plate.